An advance in a speedy type of microchip could help engineers integrate computers’ short-term and long-term memory.

For all the recent advances in the speed of computers, their command centers remain relatively inefficient. A central processor does all the thinking and quickly stores a bunch of 1s and 0s on a chip called dynamic random access memory, or DRAM. But DRAM only works when the computer is on, so it can serve only as short-term memory. Data needed for the long haul has to be store...